<template>
  <div class="star star-24" :class="`star-`+size">
    <span class="star-item" v-for="(sc, index) in starClasses" :class="sc" :key="index">

    </span>
  </div>
</template>

<script>
  // 类名常量
  const CLASS_ON = 'on'
  const CLASS_HALF = 'half'
  const CLASS_OFF = 'off'
  export default {
    props: {
      score: Number,
      size: Number
    },

    computed: {
      /**
       * 3.2: 3+0+2
       * 3.5: 3+1+1
       */
      starClasses () {
        const {score} = this
        const scs = []
        // 向 scs 中添加 n 个 ‘CLASS_ON’
        const scoreInteger = Math.floor(score)
        for (let i = 0; i < scoreInteger; i++) {
          scs.push(CLASS_ON)
        }
        // 想 scs 中添加 0/1个 ‘CLASS_HALF’
        if (score*10 - scoreInteger*10 >= 5){ // 小数不精确，所以 *10 计算
          scs.push(CLASS_HALF)
        }
        // 向 scs 中添加 n 个‘CLASS_OFF’
        while (scs.length < 5){ // 就用下 while
          scs.push(CLASS_OFF)
        }
        return scs
      }
    }
  }
</script>

<style lang="stylus" rel="stylesheet/stylus">
  @import "../../common/stylus/mixins.styl"
  .star //2x图 3x图
    float left
    font-size 0
    .star-item
      display inline-block
      background-repeat no-repeat
    &.star-48
      .star-item
        width 20px
        height 20px
        margin-right 22px
        background-size 20px 20px
        &:last-child
          margin-right: 0
        &.on
          bg-image('./images/star48_on')
        &.half
          bg-image('./images/star48_half')
        &.off
          bg-image('./images/star48_off')
    &.star-36
      .star-item
        width 15px
        height 15px
        margin-right 6px
        background-size 15px 15px
        &:last-child
          margin-right 0
        &.on
          bg-image('./images/star36_on')
        &.half
          bg-image('./images/star36_half')
        &.off
          bg-image('./images/star36_off')
    &.star-24
      .star-item
        width 10px
        height 10px
        margin-right 3px
        background-size 10px 10px
        &:last-child
          margin-right 0
        &.on
          bg-image('./images/star24_on')
        &.half
          bg-image('./images/star24_half')
        &.off
          bg-image('./images/star24_off')
</style>
